Focusing lamp with focusable reserve light bulb



June 20, 1933. O BERG FOCUSING LAMP WITH FOCUSABLE RESERVE LIGHT BULB Filed-July 23, 1932 Patented June 20, 1933 rarest MAURICE O. BERG, OF CHICAGO, ILLINOIS FOCUSING LAM]? WITH FOCUSABLE RESERVE LIGHT BULB Application filed July 23,

My invention relates to electric lamps and in its general objects aims to provide simple means, operable from the exteriorof the lamp, for effectively substituting one lamp bulb for another bulb without requiring either a manual handling of the bulbs or any disassembling of the lamp.

In automobile practice, it is highly important that each headlight, tail lamp, and spot light should function continuously when the car is driven at night, and with that in mind that car owner usually carries a reserve of lamp bulbs adapted to be substituted for those which burn out. However, such a replacing of a burnt-out or otherwise damaged lamp bulb in the commonly used automobile lamps involves considerable time and cfi'ort, even for a man, because automobile lanips usually have their frontal mem- 20 here attached tightly with a view to excluding both dirt and moisture.

For example, with automobile headlights, the frontal lens is usually mounted in a lens ring which is clamped against the body of the lamp and against the mouth of the refiector by a spring latching means which exerts sufficient pressure to prevent the assembled lens front from being loosened by jarring, and which means also compress the 30 packing or sealing ring which is usually disposed between the lens and the mouth end of the reflector. Owing to this firm securing, a

considerable effort is required for detaching the lens front so that a new lamp bulb can 35 be substituted manually for the defective one, and particularly so when mud or clay has hardened on the lamp at the juncture of the lens ring with the lamp body.

Moreover, with many headlights, the user 40 must be careful that the sealing ring does not drop out when the lens front is detached, and with many types of lenses, he must likewise be careful to replace the lens front in the same rotational position with respect to the lamp body.

My present invention aims to reduce the above recited diiiiculties and delays by providing one or more reserve lamp bulbs within the lamp, any one of which can instantly be substituted for the burnt-out bulb by a 1932. Serial No. 624,248.

provide an arrangement for this purpose which will be easily manufactured and in expensive, which can readily be attached both to commercial headlights and to many other types of electric lamps, and which can also be employed as a convenient means for varying the intensity of the light of the lamp by permitting lamp bulbs of different candlepower to be sustituted instantly for one another.

More particularly, my invention aims to provide simple and esaily attached means for supporting a plurality of lamp bulbs in such a manner that any one of these bulbscan selectiveiy be moved into or out of the normal operative position for the light-emitting bulb of the lampas for example, to the po sition in which the bulb is disposed at the focus of a reflector forming part of the lamp, or in effective position with respect to the lensof the lamp. For this purpose, my invention desirably provides means whereby each lamp bulb can be moved out of such a normal operative position while another bulb is moved to this position, so that the desired interchange of bulbs can be effected by a single manipulation.

In addition, my invention aims to provide simple means for yieldingly latching all of the bulbs against movement when any one of these is in the normal operative position.

In a still further aspect, my invention provides means whereby current will be supplied only to the lamp bulb which is in the said normal operative position, and desirably provides simple means whereby the needed connection to the current-supply circuit will. be made automatically whenever a lamp bulb is moved into the said position.

Illustrative of my invention,

Fig. 1 is a fragmentary front elevation of an automobile headlight equipped with my invention, with a part of the lens broken away.

Fig. 2 is a fragmentary side elevation of the same headlight, partially in a vertical section.

Fig. 3 is an enlarged perspective view of the bulb-holding member of Figs. 1 and 2, including only part of the stem of this member.

Fig. 4 is an enlarged horizontal section through the circuit-closing contact member and the adjacent portion of the lamp bulb which is in the operative position, taken along the line 14 of Fig. 2.

Since my invention is particularly suited for use with automobile headlights, and since the operative lamp bulb in such a headlight usually is disposed in effective cooperation either to a focusing reflector or to a lens, Figs. 1 and 2 show portions of a headlight including both a forwardly open concave reflector 1 and a lens 2.

This lens is here shown as of a type including a central concave-convex portion 2A and also including vertical flutings 2B, but neither the shape of the reflector or the arrangement of the light-retracting formations in the lens are material to my invention, so long as the corresponding embodiment provides for interchangeably disposing a plurality of lamp bulbs in a position in which the light emitted by a single one of these bulbs will be redirected by the reflector and the lens in the manner for which one or the other (or both) of these last named lamp parts were designed.

As here shown, the reflector 1 is supported in any customary manner within an also forwardly open cup-shaped lamp body 3, the mouth end of which lamp body is latched by any suitable means to the lens ring 4 in which the lens 2 is mounted. Instead of mounting a lamp socket centrally in the rear end of the reflector after the usual manner for holding a single lamp bulb, I provide a bulb-holding member designed for supporting two or more lamp bulbs and supported so that it can be moved to interchange the positions of the bulbs.

As shown in Figs. 1 to 3, this bulb-holding member includes a hub 5 brazed to arms 6 and 7 which extend in diverging planes radial of the hub, the outer end of each such arm being brazed to a socket 8 designed for firmly gripping a lamp bulb. This hub. arm and socket assembly is disposed within the concave reflector 1, desirably with the rear end of the hub bearing against the inner face of the reflector, and the hub is fast upon the forward end of astem 9 which coaxial with the hub. This stem extends through alined perforations in the reflector and the body 3 of the lamp, and is fastened to a knob 10 (disposed outside the lamp) by a pin 11, and a' spring washer 12 interposed between the said knob and the lamp body prevents any rattling or other undesired movement of the resulting assembly.

With the just described two-armed construction of the bulb-holding member, the sockets 8 preferably have their axes A converging forwardly, and these sockets are equally spaced from the axis 12 of the hub. Moreover, the perforations in the reflector and the lamp body, through which the stem 9 extends, are so located that this stem is disposed at a suitable rearwardly opening angle to the axis 18 of the reflector, and so that the axis of A of either lamp socket will aline with the axis of the reflector when the bulb-holding member is suitably rotated.

In practice, this location of the said perforations can easily be obtained by having the axes of the alined perforations in the reflector and the lamp body at the same angle 20 with the axis of the reflector (or lens, or both) as the angle 20 between the axis of each lamp socket 8 and the axis of the holder stem 9.

lVith the bulb-holding member constructed. entirely of metal, each socket 8 will be grounded to bot-lithe metal lamp back 3 and the reflector 1 when this member is attached as above described; and the spring washer 12 will enhance the firmness of this connection, thereby electrically connecting the shell terminal 14 of each lamp bulb to the lamp body which is grounded (as shown diagrammatically at 15 in Fig. 2) to one terminal of the source of current in the usual manner.

For the companion circuit connection, I provide a terminal 17 insulated from the reflector and the lamp body and supported coaxial with the reflector, and I desirably also provide spring means continuously urging this terminal forwardly of the lamp along the reflector axis 13. For example, Fig. 4. shows a plunger type terminal 17 as slid ably mounted in a hollow insulating body 18 and as continually urged forward by a spring 29 interposed between this terminal and a metal strip 24: to the outer end of which strip the ungrounded circuit wire 16 is soldered.

The forward end of the hollow insulating body 18 extends slidably through an axial perforation in the reflector 1, and the rear end of this insulator houses a plug 21 of insulating material which is fastened both to the said insulator and to the shank of a screw 22by a cross-pin 3, as shown in Fig. a. This screw is threaded through a central, opening in the back of the lamp body 3 and has its head 22A disposed behind this lamp body, so that the screw cooperates with the central perforation in the reflector for holding the insulated terminal 17 axial of the reflector. Moreover, a rotation of the screw in either direction will also adjust the position of the insulator 18 so as to vary the pressure of the spring 29, thereby compensating for possible irregularities in the assembling, such as may occur when the needed perforations of the bulb-holding member.

are made on an already installed head lamp by an ordinary mechanic. 1

l he forward end of the insulated terminal 17 preferably has its radially outer portion 17A decidedly forwardly 'convexed and its central portion 17]?) forwardly concavod. l Vith this terminal end thus formed, and with the arms 6 and 7 of the bulb-holding member disposed at suitable angles to the plane of the base of the hub 5, the axial terminal 25 of any lamp bulb which is being swung toward alinement with the insulated terminal 17 will ride up on the convexed tip portion 17A and then snap into the concavity 17B, thereby causing the spring 29 to latch the entire bulb-holding member against rotation about the axis of the holder.

Since the insulator 18 can be made of a size slid-ably fitting the usual central bore in the reflector of the lamp, and since any mechanic can easily bore the other perforations, the entire installing of my substitute for the ordinary axial lamp socket is quite simple.

With this substitute thus attached and the bulb-holding member turned so that one bulb terminal is latched by the insulated circuit terminal 17, and with the lens front then replaced, the user not only has one lamp bulb L in effective operative position but also has a reserve bulb R disposed within the lamp itself. Y

Since the glass portion of every such bulb customarily is quite thin and transparent, and since the total size of such an incandescent lamp is quite small in proportion to the surface area of the reflector, I have found in practice that there is no appreciable diminution of the light projected by the headlight, no shadow cast by the bulb or the holder, and no other material disturbance of the light distribution.

With even a single reserve bulb thus available within the lamp, the user has these added advantages: If the operating bulb burns out, all he needs to do is to turn the knob 10 sufficiently to swing the reserve bulb into axial alinement with the reflector. And, since the reserve bulb lights up automatically as soon as it is in the needed position, the user does not even need to look into the headlight while thus changing bulbs. Nor does he need to pay any attention to the burned out bulb at that time, since that is automatically swung out of the way by the same movement Thus the needed substitution can be made instantly, even by a child, leaving the garage man to substitute a fresh bulb for the burnt out one on the other arm of the holder at the end of the day or trip. Moreover, the condition By supporting the lamp sockets 8 so that their axes all converge forwardly toward the axis 12 of the manually rotatable stem 9 at an angle 26 (Fig. 3) which is equal to the rearwardly open angle between the axis 13 of the reflector and the axis of the said stem, I am able to dispose each lamp bulb L coaxial with reflector when that bulb is lit, with out requiring such a spacing between the op erative bulb and the rear end of the reflector as would then dispose the filament of the bulb far ahead of the focus of the reflector.

Thus, it will be obvious from Fig. 2, that the'terminal 17 can be almost flush with the rear end of the reflector and that the adjacent socket 8 only needs to be spaced by a quite short distance from this reflector end, so that I can readily dispose the filament of the lit bulb in focused relation to a parabolic reflector of the size and shape commonly employed for automobile headlights, and my multiple-bulbsupporting mechanism can readily be applied to the now commercial types of automobile headlights by any mechanic.

The heretofore proposed arrangements for permitting such an interchangeable disposing of one of several lamp bulbs with its filament at the axis of a reflector having usually disposed'the rotatable stem coaxial with the reflector, so that the curvature of the rear end of the reflector made it necessary to position the operative lamp bulb so far forward from the rear end of the reflector that the filament of this bulb was nowhere near the focus of the reflector, thereby enormously reducing the concentration of the light projected by the reflector.

Moreover, in comparison with other heretofore proposed constructions, my construction and arran ement eliminates the need of providing a greater spacing between the rear ends of the reflector and the back of the lamp body 3 than that commonly found in automobile headlights, requires only one auxiliary perforation to be punched in the reflector, and disposes the holder so that this does not noticeably interfere with the uniformity of the projected light.

However, while 1 have heretofore described the use of my invention for merely interchanging lamp bulbsof equal candlepower, the effective size of the bulbs in the several sockets is obviously immaterial to the operation of my lamp attachment, so that my reserve bulb equipment can be employed also as a means for varying the intensity of the headlight. For example, if the user ordinarily employs a 21 candle-power lamp bulb in the headlights on his car for city street driving, he can change instantly to more intense lighting for highway driving by using 32 candle-power bulbs as the reserves. Thus my invention can serve also as a simple and inexpensive substitute for lamp-dimming arrangements.

Moreover, it will be obvious (even without additional drawings) that the. number of sockets on my bulb-holding member can be increased by suitably increasing the number of the radial arms, so that my invention would readily afford more than a single reserve bulb in each lamp.

It will likewise be obvious that the heretofore described embodiment of my invention (in which the interchangeable bulbs are firmly supported by a single movable memher, and in which this member is rotatable) is merely illustrative, since many changes from the disclosed construction and arrangement might be made without departing either from the spirit of my invention or from the appended claims. So also, it will be evident that the providing of a plurality of interchangeably positional lamp bulbs for effective use with other parts of a lamp is not dependent on the general construction or purpose of the lamp. Hence I do not wish to be limited to the use of my invention in connection with automobile lamps, since it could be employed to equal advantage in connection with lamp designed for many other purposes.

I claim as my invention:

1. A focusing lamp comprising a generally cup-shaped and forwardly open lamp body, a forwardly concaved reflector supported in the said body; a bulb-supporting member including a stem extending forwardly through rearward portions of both the lamp body and the reflector and having its axis intersecting and disposed at a rearwardly opening angle to the axis of the reflector, and also including at least two sockets disposed at equal distances from the axis of the stem; and lamp bulbs respectively mounted in and coaxial with the said socket elements, each lamp bulb having a rearwardly directed axial lamp terminal; the said member being rotatable about the axis of its stem to dispose any one of said lamp bulbs at the focus of the reflector; each socket having its axis converging forwardly toward the axis of the said stem at an angle equal to the aforesaid angle between the axis of the stem and the axis of the reflector a circuit terminal insulated from both the lamp body and the reflector and presenting a contact tip substantially at the axis of the reflector, the said tip contacting with the axial lamp terminal of the lamp bulb disposed at the focus of the reflector; and a. current-supply circuit having its terminal connected respectively to the said circuit terminal and to the other terminal of all of the lamp bulbs.

2. A focusing lamp comprising a forwardly concaved reflector, a bulb supporting member including a stem extending through the wall of the reflector into the same and having its axis intersecting and disposed at a rear- Wardly open angle to the axis of the reflector, and also including at least two sockets disposed at equal distances from the axis of the stem, and lamp bulbs respectively mounted in and coaxial with the said socket elements, a

contact element located behind the path of the sockets and in the axis of the reflector, means whereby said member may be rotated about the axis of its stem to dispose any one of the lamp bulbs at the focus of the reflector and in electrical contact with the contact element in the axis of the reflector, each socket having its axis converging toward the axis of the said stem at an angle equal to the aforesaid angle between the axis of the stem and the axis of the reflector.

3. A focusing lamp as per claim 2, in which the member includes arms connecting the stem respectively with the sockets, each arm having its major portion flattened along a plane diametric of the stem so as to reduce the casting of shadows by the arms.

4. A focusing lamp comprising a concave reflector, a rotatable stem extending into the reflector and located obliquely to the longitudinal axis of the reflector, a plurality of lamp holding socket members carried by the stem and disposed in forwardly convergent relation to each other, said socket members moving between an angular relation with respect to the longitudinal axis of the reflector and a position in said axis on the rotation of the stem on its axis, and an electric contact element mounted in the longitudinal axis of the reflector and located behind the path of the socket elements, said contact element being adapted to be electrically contacted by any one of the lamps placed in the socket members when such lamp is in the said longitudinal axis of the reflector.

Signed at Chicago, Illinois, July 20th,

MAURICE O. BERG. 

